/*
 *  Licensed to the Apache Software Foundation (ASF) under one or more
 *  contributor license agreements.  See the NOTICE file distributed with
 *  this work for additional information regarding copyright ownership.
 *  The ASF licenses this file to You under the Apache License, Version 2.0
 *  (the "License"); you may not use this file except in compliance with
 *  the License.  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */

package org.apache.tomcat.jni;

/**
 * OS
 *
 * @author Mladen Turk
 */
public class OS {

	public static final int LOG_EMERG = 1;
	public static final int LOG_ERROR = 2;
	public static final int LOG_NOTICE = 3;
	public static final int LOG_WARN = 4;
	public static final int LOG_INFO = 5;
	public static final int LOG_DEBUG = 6;
	/* OS Enums */
	private static final int UNIX = 1;
	public static final boolean IS_UNIX = is(UNIX);
	private static final int NETWARE = 2;
	public static final boolean IS_NETWARE = is(NETWARE);
	private static final int WIN32 = 3;
	public static final boolean IS_WIN32 = is(WIN32);
	private static final int WIN64 = 4;
	public static final boolean IS_WIN64 = is(WIN64);
	private static final int LINUX = 5;
	public static final boolean IS_LINUX = is(LINUX);
	private static final int SOLARIS = 6;
	public static final boolean IS_SOLARIS = is(SOLARIS);
	private static final int BSD = 7;
	public static final boolean IS_BSD = is(BSD);
	private static final int MACOSX = 8;
	public static final boolean IS_MACOSX = is(MACOSX);

	/**
	 * Check for OS type.
	 *
	 * @param type OS type to test.
	 */
	private static native boolean is(int type);

	/**
	 * Get the name of the system default character set.
	 *
	 * @param pool the pool to allocate the name from, if needed
	 */
	public static native String defaultEncoding(long pool);

	/**
	 * Get the name of the current locale character set.
	 * Defers to apr_os_default_encoding if the current locale's
	 * data can't be retrieved on this system.
	 *
	 * @param pool the pool to allocate the name from, if needed
	 */
	public static native String localeEncoding(long pool);

	/**
	 * Generate random bytes.
	 *
	 * @param buf Buffer to fill with random bytes
	 * @param len Length of buffer in bytes
	 */
	public static native int random(byte[] buf, int len);

	/**
	 * Gather system info.
	 * <PRE>
	 * On exit the inf array will be filled with:
	 * inf[0]  - Total usable main memory size
	 * inf[1]  - Available memory size
	 * inf[2]  - Total page file/swap space size
	 * inf[3]  - Page file/swap space still available
	 * inf[4]  - Amount of shared memory
	 * inf[5]  - Memory used by buffers
	 * inf[6]  - Memory Load
	 * <p>
	 * inf[7]  - Idle Time in microseconds
	 * inf[8]  - Kernel Time in microseconds
	 * inf[9]  - User Time in microseconds
	 * <p>
	 * inf[10] - Process creation time (apr_time_t)
	 * inf[11] - Process Kernel Time in microseconds
	 * inf[12] - Process User Time in microseconds
	 * <p>
	 * inf[13] - Current working set size.
	 * inf[14] - Peak working set size.
	 * inf[15] - Number of page faults.
	 * </PRE>
	 *
	 * @param inf array that will be filled with system information.
	 *            Array length must be at least 16.
	 */
	public static native int info(long[] inf);

	/**
	 * Expand environment variables.
	 *
	 * @param str String to expand
	 * @return Expanded string with replaced environment variables.
	 */
	public static native String expand(String str);

	/**
	 * Initialize system logging.
	 *
	 * @param domain String that will be prepended to every message
	 */
	public static native void sysloginit(String domain);

	/**
	 * Log message.
	 *
	 * @param level   Log message severity. See LOG_XXX enums.
	 * @param message Message to log
	 */
	public static native void syslog(int level, String message);

}
